Add joystick reading example, for documentation.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

Makefile

@@ -111,6 +111,10 @@ bench: Makefile bench.o $(STATICLIB)
 	@printf "  BENCH   %s\n" $(STATICLIB)
 	@$(CC) $(CPPFLAGS) -g -o bench bench.c $(STATICLIB) && ./bench
 
+joystick: Makefile joystick.o $(STATICLIB)
+	@printf "  JOTST   %s\n" $(STATICLIB)
+	@$(CC) $(CPPFLAGS) -g -o joystick joystick.c $(STATICLIB) && ./joystick
+
 check:
 	@$(CHECK) $(CHECK_FLAGS) $(CPPFLAGS) $(SRCS) bench.c
 

joystick.c

@@ -0,0 +1,84 @@
+/* Simple example of how to use libuEv with Linux joystick API
+ *
+ * Copyright (c) 2014  Joachim Nilsson <troglobit()gmail!com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <err.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "uev.h"
+
+#define UNUSED(arg) arg __attribute__ ((unused))
+
+struct js_event {
+	uint32_t time;		/* event timestamp in milliseconds */
+	int16_t  value;		/* value */
+	uint8_t  type;		/* event type */
+	uint8_t  number;	/* axis/button number */
+} e;
+
+static void joystick_cb(uev_ctx_t *UNUSED(ctx), uev_t *w, void *UNUSED(arg), int UNUSED(events))
+{
+	if (read (w->fd, &e, sizeof(e)) < 0)
+		errx(errno, "Failed reading joystick event");
+
+	switch (e.type) {
+	case 1:
+		if (e.value) printf("Button %d pressed\n", e.number);
+		else 	     printf("Button %d released\n", e.number);
+		break;
+
+	case 2:
+		printf("Joystick axis %d moved, value %d!\n", e.number, e.value);
+		break;
+	}
+}
+
+int main(void)
+{
+	int       fd = open("/dev/input/js1", O_RDONLY, O_NONBLOCK);
+	uev_t     js1_watcher;
+	uev_ctx_t ctx;
+
+	if (fd < 0)
+		errx(errno, "Cannot find a joystick attached.");
+
+	uev_init(&ctx);
+	uev_io_init(&ctx, &js1_watcher, joystick_cb, NULL, fd, UEV_READ);
+
+	puts("Starting, press Ctrl-C to exit.");
+
+	return uev_run(&ctx, 0);
+}
+
+/**
+ * Local Variables:
+ *  compile-command: "gcc -o joystick joystick.c io.o timer.o signal.o main.o"
+ *  version-control: t
+ *  indent-tabs-mode: t
+ *  c-file-style: "linux"
+ * End:
+ */